BACKGROUND OF THE INVENTION
Technical Field
[0001] The present invention relates to a musical note generation device, an electronic
musical instrument, a method, and a storage medium.
Background Art
[0002] In an acoustic piano, when the damper pedal is not depressed, dampers arranged corresponding
to the keys contact the strings while the keys are not depressed and are lifted from
contact with the strings when the keys are pressed. Moreover, hammers that are actuated
by pressing the keys strike the strings. Meanwhile, when the damper pedal is depressed,
the dampers that provide damping for the keys are all lifted. In this state, if any
of the keys are pressed and the string corresponding to that key is struck, a note
corresponding to the vibration of that string is produced, and all of the other strings
resonate with the vibration of that string and produce resonant tones. The vibration
of the string that was struck as well as the resonance of the resonant tones continue
for a long period of time even after the key is released. These resonant tones are
one of the characterizing features of piano sounds.
[0003] In conventional electronic pianos, simulating the resonant tones of an acoustic piano
is typically accomplished with signal processing techniques involving a combination
of feedback filters such as reverbs and resonators, for example.
[0004] Moreover, one conventional example of an approach to reproducing the complex sound
image profile of string resonance is the following resonant tone sound image generation
device (see Patent Document 1, for example). A resonant tone generator includes string
resonance circuit groups in which a plurality of string resonance circuits are grouped
together. Each string resonance circuit is a digital filter having a resonant frequency
corresponding to harmonics of musical notes. When a musical note signal is input by
pressing a key, a string resonance signal corresponding to the musical note signal
is input to a convolution operation processor and convolved with a pre-measured impulse
response. The convolved string resonance signal is then synthesized by an adder and
output. The respective output signals from the string resonance circuit groups are
convolved with impulse responses from mutually different sound source positions defined
as if to be on the bridge of an acoustic piano occupying the same space.
[0005] Patent Document 1: Japanese Patent Application Laid-Open Publication No.
2007-193129
[0006] US 2009/000462 A1 discloses generating musical piano resonance tones when sustain pedal is depressed.
The resonance is provided on a synthesized musical tone fed to individual gain circuits
provided for specific pitches, mixed and sent to resonance circuits comprising benches
of resonating filters each tuned to a specific note with respective harmonics. The
output of these resonance circuits are added together.
[0007] JP 2009175677 A discloses creating sustain resonance for piano tone simulator, and provides a set
of three convolution filters which are dedicated to simulating the soundboard response
for a certain range of tones (i.e. low notes, middle range, and high notes).
[0008] However, in the conventional technology based on the feedback filter signal processing
techniques described above, it is difficult to achieve a realistic sound equivalent
to the resonant tones of an acoustic piano.
[0009] One advantage of the present invention lies in making it possible to generate natural
resonant tones similar to those of an acoustic piano.
[0010] Accordingly, the present invention is directed to a scheme that substantially obviates
one or more of the problems due to limitations and disadvantages of the related art.
SUMMARY OF THE INVENTION
[0011] Additional or separate features and advantages of the invention will be set forth
in the descriptions that follow and in part will be apparent from the description,
or may be learned by practice of the invention. The objectives and other advantages
of the invention will be realized and attained by the structure particularly pointed
out in the written description and claims thereof as well as the appended drawings.
The present invention is defined by a device according to appended claim 1, a method
according to claim 9 and a non-transitory storage medium according to claim 10.
[0012] To achieve these and other advantages and in accordance with the purpose of the present
invention, as embodied and broadly described, in one aspect, the present disclosure
provides a musical note generation device, including: a plurality of keys, the plurality
of keys respectively being associated with pitch information; and at least one processor,
the at least one processor performing the following processes: an attenuated sound
waveform data generation process of generating attenuated sound waveform data by respectively
reducing, among frequency components included in first sound waveform data corresponding
to the pitch information associated with a specified key, amplitudes of respective
frequency components of a fundamental tone and harmonics of the fundamental tone corresponding
to a pitch indicated by the pitch information; a convolution operation process that
convolves the attenuated sound waveform data generated by the attenuated sound waveform
data generation process with at least one of a plurality of second sound waveform
data sets respectively corresponding to a high sound range side impulse response and
a low sound range side impulse response, so as to generate third sound waveform data;
and an output process of outputting piano sound waveform data generated on the basis
of the third sound waveform data generated by the convolution operation process.
[0013] In another aspect, the present disclosure provides a musical note generation device
according to dependent claim 6.
[0014] In another aspect, the present disclosure provides a method to be executed by a processor
in an electronic musical instrument, including: an attenuated sound waveform data
generation process of generating attenuated sound waveform data by respectively reducing,
among frequency components included in first sound waveform data corresponding to
pitch information associated with a specified key, amplitudes of respective frequency
components of a fundamental tone and harmonics of the fundamental tone corresponding
to a pitch indicated by the pitch information; a convolution operation process that
convolves the attenuated sound waveform data generated by the attenuated sound waveform
data generation process with at least one of a plurality of second sound waveform
data sets respectively corresponding to a high sound range side impulse response and
a low sound range side impulse response, so as to generate third sound waveform data;
and an output process of outputting piano sound waveform data generated on the basis
of the third sound waveform data generated by the convolution operation process.
[0015] In another aspect, the present disclosure provides a non-transitory storage medium
having stored therein instructions that cause a processor in an electronic musical
instrument to perform the following processes: an attenuated sound waveform data generation
process of generating attenuated sound waveform data by respectively reducing, among
frequency components included in first sound waveform data corresponding to pitch
information associated with a specified key, amplitudes of respective frequency components
of a fundamental tone and harmonics of the fundamental tone corresponding to a pitch
indicated by the pitch information; a convolution operation process that convolves
the attenuated sound waveform data generated by the attenuated sound waveform data
generation process with at least any one of a plurality of second sound waveform data
sets respectively corresponding to a high sound range side impulse response and a
low sound range side impulse response, so as to generate third sound waveform data;
and an output process of outputting piano sound waveform data generated on the basis
of the third sound waveform data generated by the convolution operation process.
[0016] It is to be understood that both the foregoing general description and the following
detailed description are exemplary and explanatory, and are intended to provide further
explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The detailed descriptions below are intended to be read with reference to the following
figures in order to gain a deeper understanding of the present application.
FIG. 1 is a block diagram illustrating an example of an embodiment of an electronic
musical instrument.
FIG. 2 is a block diagram illustrating an embodiment of a damper sound effect generator.
FIG. 3 illustrates an example of the characteristics of a comb filter that attenuates
the fundamental resonant tones of strings in recorded piano sounds.
FIG. 4 illustrates an example of characteristics for settings for a high note side
application factor and a low note side application factor.
FIG. 5 is a block diagram illustrating an example of an embodiment of an FFT convolver.
FIG. 6 is an explanatory drawing of a method of recording impulse response waveform
data (second sound waveform data).
FIGs. 7A to 7D are flowcharts illustrating examples of processes in the electronic
musical instrument.
DETAILED DESCRIPTION OF EMBODIMENTS
[0018] An embodiment of the present invention will be described in detail below with reference
to figures. The present embodiment relates to an electronic musical instrument that
simulates an acoustic piano. Waveform data (first sound waveform data) is created
by recording the sounds produced when the keys of an acoustic piano are pressed, and
this data is stored in a waveform memory in a piano sound source (an integrated circuit).
Then, when the keys of an electronic piano are pressed, piano sound waveform data
is generated by reading the waveform data corresponding to the pitches of the pressed
keys from the waveform memory.
[0019] Moreover, in the present embodiment, to simulate the resonance from string vibration
that occurs when the damper pedal of an acoustic piano is depressed, impulse response
waveform data (second sound waveform data) for resonant tones obtained by causing
the acoustic piano to vibrate while depressing the damper pedal of the acoustic piano
is recorded in advance and stored in a memory of the electronic musical instrument.
Then, a convolution operation process of convolving the first sound waveform data
corresponding to pressed keys with the impulse response waveform data (second sound
waveform data) is performed, and resonant tone waveform data (third sound waveform
data) is generated. Next, piano sound waveform data is generated by mixing together
the first sound waveform data and the resonant tone waveform data (third sound waveform
data) in a ratio corresponding to the amount by which the damper pedal is depressed.
Then, the generated piano sound waveform data is output.
[0020] The impulse response waveform data (second sound waveform data) recorded while the
damper pedal is depressed is recorded while all of the strings are in a free state;
that is, a state in which all of the strings can resonate and vibrate to produce sound.
Therefore, the impulse response waveform data (second sound waveform data) includes
frequency characteristics for a state equivalent to when all of the strings are producing
sound and also includes harmonic characteristics of strings producing sound due to
keypresses. As a result, when the first sound waveform data produced from the waveform
memory when a key is pressed is convolved with the impulse response waveform data
(second sound waveform data) including these frequency characteristics, the waveform
data components of the pitch corresponding to the keypress that are included in both
types of waveform data are undesirably emphasized, which produces unnatural resonant
tones.
[0021] As a countermeasure, in the present embodiment, a filtering calculation process is
performed to generate attenuated sound waveform data by respectively reducing, from
the frequency components included in the waveform data (first sound waveform data)
produced from the waveform memory when a key is pressed, the amplitudes of the respective
frequency components of the fundamental tone and harmonics of the pitch corresponding
to the keypress. Then, an operation process of convolving the attenuated sound waveform
data generated by the filtering calculation process with the abovementioned impulse
response waveform data is performed to generate the resonant tone waveform data (third
sound waveform data). In this manner, the present embodiment makes it possible to
generate natural resonant tones.
[0022] Furthermore, in the present embodiment, for each set of the first sound waveform
data respectively corresponding to one or more pitches respectively produced from
the waveform memory in response to presses of a plurality of keys, a plurality of
filtering calculation processes are performed to respectively reduce, from the frequency
components included in the first sound waveform data, the amplitudes of the respective
frequency components of the fundamental tones and harmonics of the pitches corresponding
to the first sound waveform data. Next, an operation process is performed to convolve
the attenuated sound waveform data generated by the filtering calculation processes
with any one of a plurality of sets of second sound waveform data that is different
from the first sound waveform data. For example, a storage unit that stores effect
application factor data for a high sound range side (hereinafter, "high note side")
and effect application factor data for a low sound range side (hereinafter, "low note
side") of a keyboard of a piano is included, and a first convolution operation process
of convolving attenuated sound waveform data multiplied by the high note side effect
application factors stored in the storage unit with the second sound waveform data
for the high note side among the plurality of sets of second sound waveform data,
as well as a second convolution operation process of convolving attenuated sound waveform
data multiplied by the low note side effect application factors stored in the storage
unit with the second sound waveform data for the low note side among the plurality
of sets of second sound waveform data, are performed. Finally, resonant tone waveform
data (third sound waveform data) is generated by mixing together the outputs of the
convolution operation processes. In this way, the present embodiment makes it possible
to, regardless of which keys are pressed, output natural sounds of the type produced
when a grand piano is played while depressing the damper pedal. In the present embodiment,
application factors are determined from the high sound side effect application factors
and the low sound side application factors. The input first sound waveform data is
divided up by these application factors, and the third sound waveform data is generated
after respectively performing a high sound side convolution operation process and
a low sound side convolution operation process. This makes it possible to output natural
sounds regardless of which keys are pressed.
[0023] Moreover, in another embodiment, the third sound waveform data may be generated by
convolving the attenuated sound waveform data with any one of a plurality of sets
of second sound waveform data respectively corresponding to a high sound range side
impulse response and a low sound range side impulse response. In other words, when
a key on the high sound range side is pressed from among the plurality of keys, a
process of convolving the attenuated sound waveform data with the second sound waveform
data corresponding to the high sound range side impulse response is performed, and
a process of convolving the attenuated sound waveform data with the second sound waveform
data corresponding to the low sound range side impulse response is not performed.
Conversely, when a key on the low sound range side is pressed from among the plurality
of keys, a process of convolving the attenuated sound waveform data with the second
sound waveform data corresponding to the low sound range side impulse response is
performed, and a process of convolving the attenuated sound waveform data with the
second sound waveform data corresponding to the high sound range side impulse response
is not performed. This type of embodiment may be implemented as well.
[0024] FIG. 1 is a block diagram illustrating an example of an embodiment of an electronic
musical instrument 100. The electronic musical instrument 100 includes a damper sound
effect generator 101, a piano sound source 102; a central processing unit (CPU) 103;
a randomly accessible memory 104; multipliers 105 and 106; adders 107 and 108; a general-purpose
input/output (GPIO) 130 to which a keyboard 140, a damper pedal 150, and a switch
unit 160 are connected; and a system bus 170. The damper sound effect generator 101,
the piano sound source 102, the multipliers 105 and 106, and the adders 107 and 108
may be implemented using a single-chip or multi-chip digital signal processor (DSP)
integrated circuit, for example.
[0025] The keyboard 140 is a keyboard with which a performer inputs a piano performance
and includes 88 keys, for example.
[0026] The damper pedal 150 is depressed by the performer to create an effect simulating
the behavior of the damper pedal in an acoustic piano.
[0027] The switch unit 160 includes general-purpose switches such as a power switch, a volume
switch, and tone color selection switches as well as a switch for specifying the amount
of damper pedal effect to apply, a switch for changing the temperament, a switch for
changing the master tuning, and the like.
[0028] The GPIO 130 detects keypress and key release information of the keys on the keyboard
140, ON (depressed) and OFF (not depressed) information of the damper pedal 150, and
operation information of the switches in the switch unit 160 and notifies the CPU
103 of this information via the system bus 170.
[0029] The CPU 103, in accordance with control programs stored in the memory 104, executes
processes for handling information received from the performer via the GPIO 130, including
a process for keypress and key release information from the keyboard 140 and a process
for ON/OFF information from the damper pedal 150, as well as processes triggered by
operation of the switch unit 160 such as a process for power ON information, a process
for volume change information, a process for tone color selection information, a process
for changing the temperament, a process for master tuning change information, and
a process for specifying the amount of damper pedal effect to apply, for example.
As a result of these processes, the CPU 103 outputs performance information 117 that
includes note-on information, note-off information, tone color selection information,
temperament change information, master tuning change information, and the like to
the piano sound source 102 via the system bus 170. Moreover, in the present embodiment,
this performance information 117 includes damper pedal depression information 118.
This damper pedal depression information 118 is also sent to the damper sound effect
generator 101. Furthermore, the CPU 103 outputs volume change information to analog
amplifiers (not illustrated in the figure). The CPU 103 also outputs the following
to the damper sound effect generator 101 via the system bus 170: a pitch control signal
119, a resonant effect reduction amount configuration signal 120, and impulse response
waveform data (second sound waveform data) 121a and 121b that is read from the memory
104. In addition, the CPU 103 outputs a damper pedal effect application amount configuration
signal 122 to the multipliers 105 and 106 via the system bus 170.
[0030] The memory 104 stores the control programs for operating the CPU 103 and also temporarily
stores various types of working data while programs are executed. The memory 104 also
stores the impulse response waveform data (second sound waveform data) 121a and 121b,
which respectively correspond to the high note side and the low note side.
[0031] The piano sound source 102 stores, in an internal waveform memory (not illustrated
in the figure), waveform data obtained by recording sounds produced by pressing the
keys of an acoustic piano. In accordance with performance information 117 indicating
a note-on instruction from the CPU 103, the piano sound source 102 allocates a free
channel from among time-divided sound production channels (or, if there are no free
channels, a channel obtained by silencing the oldest channel) and then uses this sound
production channel to start reading waveform data for the specified pitch from the
internal waveform memory (not illustrated in the figure). In accordance with performance
information 117 indicating a note-off instruction from the CPU 103, the piano sound
source 102 stops reading the waveform data from the waveform memory to the sound production
channel currently producing sound for the specified pitch and then frees that sound
production channel. However, when damper pedal depression information 118 indicating
that the damper pedal is ON (depressed) is input, even if performance information
117 indicating a note-off instruction is input, the process of reading the waveform
data from the waveform memory continues rather than stops.
[0032] Here, the piano sound source 102 respectively stores, in the waveform memory, left
channel waveform data and right channel waveform data obtained by recording the sounds
produced by pressing the keys of an acoustic piano in stereo. Moreover, upon receiving
performance information 117 indicating a note-on instruction, the piano sound source
102 respectively allocates a sound production channel for the left channel and a sound
production channel for the right channel and then uses the allocated sound production
channels to start respectively reading the left channel waveform data and the right
channel waveform data from the waveform memory. The piano sound source 102 processes,
in a time-divided manner and individually for the left channel and the right channel,
the reading of a plurality of sets of waveform data using a plurality of sound production
channels corresponding to a plurality of note-on instructions. The piano sound source
102 outputs a plurality of sets of waveform data corresponding to the plurality of
note-on instructions and currently being read for the left channel to the adder 107
as first sound waveform data (L-ch) 109, and similarly outputs a plurality of sets
of waveform data corresponding to the plurality of note-on instructions and currently
being read for the right channel to the adder 108 as first sound waveform data (R-ch)
110. Moreover, the piano sound source 102 outputs the plurality of sets of waveform
data corresponding to the plurality of note-on instructions and currently being read
for the left channel to the damper sound effect generator 101. Similarly, the piano
sound source 102 outputs the plurality of sets of waveform data corresponding to the
plurality of note-on instructions and currently being read for the right channel to
the damper sound effect generator 101. The piano sound source 102 outputs note number
information for sound production channels that were newly allocated in response to
the note-on instructions to the damper sound effect generator 101 as sound production
channel information 123.
[0033] On the basis of the sound production channel information 123 input from the piano
sound source 102, for each sound production channel for which the same note number
is specified in the first sound waveform data (L-ch) 109 for the left stereo channel
input from the piano sound source 102, the damper sound effect generator 101 performs
filtering calculation processes (for each key number of 88 keys, for example) of generating
attenuated sound waveform data by respectively reducing, from the frequency components
included in the waveform data in that sound production channel, the amplitudes of
the respective frequency components of the fundamental tone and harmonics of the pitch
corresponding to the note number specified for that sound production channel. The
damper sound effect generator 101 then performs two mixing processes (one for the
high note side and one for the low note side of the keyboard of the piano) for mixing
together the outputs of the filtering calculation processes for the 88 keys for the
left channel in ratios based on the relationships between the pitches corresponding
to the filtering calculation processes and the high note side or the low note side.
The damper sound effect generator 101 then performs two convolution operation processes
(one for the high note side and one for the low note side) for convolving the waveform
data for the left channel output from the respectively corresponding mixing process
with left channel impulse response waveform data (second sound waveform data) recorded
for both the high note side and the low note side and read from the memory 104. Finally,
the outputs of the convolution operation processes are mixed together, and the resulting
third sound waveform data (L-ch) 113 for the left channel is output to the multiplier
105. The damper sound effect generator 101 also performs the same processes on the
first sound waveform data (R-ch) 110 for the right stereo channel input from the piano
sound source 102, and then outputs the resulting third sound waveform data (R-ch)
114 for the right channel to the multiplier 106.
[0034] Here, by operating a switch in the switch unit 160, the performer can specify the
amount of resonant tone effect to apply when the damper pedal 150 is depressed, and
the CPU 103 outputs the specified amount of effect as the damper pedal effect application
amount configuration signal 122. On the basis of this damper pedal effect application
amount configuration signal 122, the multipliers 105 and 106 respectively control
the amplitudes of the third sound waveform data (L-ch) 113 and the third sound waveform
data (R-ch) 114 output from the damper sound effect generator 101 in order to determine
the respective amounts of resonant tone for the left channel and the right channel.
[0035] The adder 107 adds together the first sound waveform data (L-ch) 109 output from
the piano sound source 102 and the third sound waveform data (L-ch) 113 output from
the damper sound effect generator 101 via the multiplier 105, and then outputs the
resulting left channel piano sound waveform data (L-ch) 115 to which the damper pedal
effect has been applied. Similarly, the adder 108 adds together the first sound waveform
data (R-ch) 110 output from the piano sound source 102 and the third sound waveform
data (R-ch) 114 output from the damper sound effect generator 101 via the multiplier
106, and then outputs the resulting right channel piano sound waveform data (R-ch)
116 to which the damper pedal effect has been applied. The piano sound waveform data
(L-ch) 115 and the piano sound waveform data (R-ch) 116 are then respectively output
to digital-to-analog (D/A) converters, analog amplifiers, and speakers (not illustrated
in the figure) to be played as stereo piano ON signals.
[0036] FIG. 2 is a block diagram illustrating an embodiment of the damper sound effect generator
101 illustrated in FIG. 1. The damper sound effect generator 101 includes a damper
sound effect generator (L-ch) 201 that processes the left channel and a damper sound
effect generator (R-ch) 202 that processes the right channel. The damper sound effect
generator (L-ch) 201 performs processes for generating damper sound effects on the
first sound waveform data (L-ch) 109 for the left channel input from the piano sound
source 102 illustrated in FIG. 1, and then outputs the resulting third sound waveform
data (L-ch) 113 illustrated in FIG. 1 to the multiplier 105. Similarly, the damper
sound effect generator (R-ch) 202 performs processes for generating damper sound effects
on the first sound waveform data (R-ch) 110 for the right channel input from the piano
sound source 102 illustrated in FIG. 1, and then outputs the resulting third sound
waveform data (R-ch) 114 illustrated in FIG. 1 to the multiplier 106.
[0037] The damper sound effect generator (L-ch) 201 and the damper sound effect generator
(R-ch) 202 have the same configuration except in that the inputs and outputs respectively
correspond to the left channel and the right channel, and therefore the following
description will only focus on the damper sound effect generator (L-ch) 201. The damper
sound effect generator (L-ch) 201 includes a filter calculation processor 203, a high
note side convolution operation processor 204a, and a low note side convolution operation
processor 204b.
[0038] The filter calculation processor 203 includes a sound production channel-comb filter
allocator 205, 88 comb filters 206 numbered from #0 (A0) to #87 (C8) and corresponding
to the pitches of the 88 keys on the keyboard of an acoustic piano, #0 to #87 high
note side multipliers 219a that multiply the outputs of the #0 to #87 comb filters
206 with high note side application factors 401a, #0 to #87 low note side multipliers
219b that similarly multiply the outputs of the #0 to #87 comb filters 206 with low
note side application factors 401b, a high note side adder 207a that adds together
(mixes together) the outputs of the #0 to #87 high note side multipliers 219a and
outputs the addition results as high note side attenuated sound waveform data 218a,
and a low note side adder 207b that similarly adds together (mixes together) the outputs
of the #0 to #87 low note side multipliers 219b and outputs the addition results as
low note side attenuated sound waveform data 218b.
[0039] The sound production channel-comb filter allocator 205, on the basis of the sound
production channel information 123 input from the piano sound source 102, allocates
and inputs waveform data that, among sets of waveform data in N note-on instruction-specific
sound production channels #0 to #N-1 for the first sound waveform data (L-ch) 109
input from the piano sound source 102 illustrated in FIG. 1, is in sound production
channels for which the same note number is specified to the comb filter 206 that,
among the 88 comb filters 206 numbered from #0 to #87, corresponds to that note number.
Here, the allocation of any waveform data in a sound production channel for the same
note number that had previously been allocated to that comb filter 206 is cleared.
This means that when the same key on the keyboard 140 illustrated in FIG. 1 is pressed
multiple times, the damper effect applied to an earlier keypress is cleared so that
the damper effect can be applied to a later keypress.
[0040] Each of the 88 comb filters 206 numbered from #0 to #87 performs a filtering calculation
process of generating and outputting note number-specific attenuated sound waveform
data by respectively reducing, from the frequency components included in the input
waveform data, the amplitudes of the respective frequency components of the fundamental
tone and harmonics of a pitch corresponding to a note number specified in that waveform
data.
[0041] As illustrated for the #0 comb filter 206 in FIG. 2, in order to perform this filtering
calculation process, the comb filter 206 includes a delayer 208 (indicated by "Delay"
in the figure) that delays the input waveform data by a specified delay length (number
of samples; hereinafter, this delay length is represented by K), a multiplier 209
that multiplies the output of the delayer 208 by a scaling factor α, and an adder
210 that adds together the input waveform data and the output of the multiplier 209
and then outputs the addition results as the note number-specific attenuated sound
waveform data. The comb filter 206 further includes a register Reg#1 211 that stores
the pitch control signal 119 specified via the system bus 170 by the CPU 103 illustrated
in FIG. 1 and supplies the delay length K to the delayer (Delay) 208, as well as a
register Reg#2 212 that stores the resonant effect reduction amount configuration
signal 120 similarly specified via the system bus 170 by the CPU 103 and supplies
the scaling factor α to the multiplier 209. Furthermore, the comb filter 206 includes
a register Reg#3 221 and a register Reg#4 222 that respectively store the high note
side application factor and the low note side application factor that are respectively
applied to the high note side multiplier 219a and the low note side multiplier 219b.
[0042] The comb filter 206 configured as described above thus forms a feed forward comb
filter. In the comb filter 206, letting the input be x[n] and the output (the note
number attenuated sound waveform data) be y[n], the comb filter 206 satisfies equation
1 below.
![](https://data.epo.org/publication-server/image?imagePath=2019/49/DOC/EPNWB1/EP17209236NWB1/imgb0001)
[0043] Given equation 1, the transfer function for the comb filter 206 can be defined as
shown below in equation 2.
![](https://data.epo.org/publication-server/image?imagePath=2019/49/DOC/EPNWB1/EP17209236NWB1/imgb0002)
[0044] To obtain the frequency characteristics of a discrete-time system expressed in the
z-domain, the substitution z = e
jω (where e is an exponent, j is a unit complex number, and ω is angular frequency)
is made, thereby allowing the transfer function given by equation 2 to be expressed
as equation 3 below.
![](https://data.epo.org/publication-server/image?imagePath=2019/49/DOC/EPNWB1/EP17209236NWB1/imgb0003)
[0045] Then, using Euler's formula, equation 3 can be rewritten as equation 4.
![](https://data.epo.org/publication-server/image?imagePath=2019/49/DOC/EPNWB1/EP17209236NWB1/imgb0004)
Therefore, from equation 4, the frequency-amplitude response of the comb filter 206
can also be expressed by equation 5.
![](https://data.epo.org/publication-server/image?imagePath=2019/49/DOC/EPNWB1/EP17209236NWB1/imgb0005)
In equation 5, the (1+α
2) term is a constant, while the 2αcos(ωK) term is a periodic function. Therefore,
as illustrated in FIG. 3, the frequency characteristics of the comb filter 206 has
periodic zero points. Here, when the delay length K is set to a sample length corresponding
to the period of the pitch assigned to the key number (one of #0 to #87) for that
comb filter 206, the frequency of the zero points in the frequency characteristics
of the comb filter 206 illustrated in FIG. 3 corresponds to the respective frequencies
of the fundamental tone and harmonics of the pitch. Thus, the comb filter 206 performs
the filtering calculation process of respectively reducing, from the frequency components
included in the input waveform data, the amplitudes of the respective frequency components
of the fundamental tone and harmonics of the pitch corresponding to the note number
specified in that waveform data. As a result, the note number-specific attenuated
sound waveform data output from the comb filter 206 exhibits frequency characteristics
in which the amplitudes of the respective frequency components of the fundamental
tone and harmonics of the pitch assigned to the key number (one of #0 to #87) for
that comb filter 206 are respectively reduced.
[0046] As described above, the delay length K set to the delayer (Delay) 208 of the comb
filter 206 corresponds to the pitch assigned to the key number (one of #0 to #87)
for that comb filter 206. However, as also described above, the CPU 103 illustrated
in FIG. 1 can supply this pitch information in advance via the system bus 170 as the
pitch control signal 119. The pitch is determined by the pitch frequency of the key
corresponding to the key number, the temperament setting specified by the performer,
and the master tuning setting similarly specified by the performer. As will be described
in more detail later (see the description of FIG. 7C), any time when the electronic
musical instrument 100 illustrated in FIG. 1 is powered on, when the performer changes
the temperament, or when the performer changes the master tuning, the CPU 103 recalculates
the pitch information corresponding to each of the comb filters 206 and then sets
this information to the register Reg#1 211 of each comb filter 206 as the pitch control
signal 119.
[0047] Moreover, from equation 5 above, changing the scaling factor α set to the multiplier
209 makes it possible to change the depth of the zero points in the frequency characteristics
illustrated in FIG. 3. The amount by which the amplitudes of the respective frequency
components of the fundamental tone and harmonics of the pitch assigned to a key number
should be respectively reduced varies depending on the key number. Therefore, for
each of the comb filters 206, the CPU 103 sets the scaling factor α corresponding
to the key number assigned to that comb filter 206 to the register Reg#2 212 of that
comb filter 206 via the system bus 170 as the resonant effect reduction amount configuration
signal 120.
[0048] For the sets of waveform data that are allocated by the sound production channel-comb
filter allocator 205 and in which note numbers corresponding to the pitches of the
key numbers #0 to #87 in the first sound waveform data (L-ch) 109 input from the piano
sound source 102 are specified, the #0 to #87 comb filters 206 respectively generate
and output note number-specific attenuated sound waveform data by respectively reducing,
from the frequency components included in that waveform data, the amplitudes of the
respective frequency components of the fundamental tones and harmonics of the pitches
corresponding to the note numbers specified in that waveform data.
[0049] The #0 to #87 high note side multipliers 219a respectively multiply the sets of note
number-specific attenuated sound waveform data output from the #0 to #87 comb filters
206 with the high note side application factors applied from the registers Reg#3 221
in the comb filters 206, and then output the results to the high note side adder 207a.
Similarly, the #0 to #87 low note side multipliers 219b respectively multiply the
sets of note number-specific attenuated sound waveform data output from the #0 to
#87 comb filters 206 with the low note side application factors applied from the registers
Reg#4 222 in the comb filters 206, and then output the results to the low note side
adder 207b. Here, the settings for the high note side application factors that are
set to the registers Reg#3 221 of the #0 to #87 comb filters 206 are determined, for
each of the key numbers associated with the #0 to #87 comb filters 206, on the basis
of characteristics such as those in the example illustrated in FIG. 4. The lower the
key number is, the lower the value of the setting determined for the high note side
application factor is, and conversely, the higher the value of the setting determined
for the low note side application factor is. The higher the key number is, the higher
the value of the setting determined for the high note side application factor is,
and conversely, the lower the value of the setting determined for the low note side
application factor is.
[0050] The high note side adder 207a adds together (mixes together) the outputs of the #0
to #87 high note side multipliers 219a and outputs the addition results to the high
note side convolution operation processor 204a as the high note side attenuated sound
waveform data 218a. Similarly, the low note side adder 207b adds together (mixes together)
the outputs of the #0 to #87 low note side multipliers 219b and outputs the addition
results to the low note side convolution operation processor 204b as the low note
side attenuated sound waveform data 218b.
[0051] In FIG. 2, when the performer depresses the damper pedal 150 illustrated in FIG.
1, the high note side convolution operation processor 204a performs a process of convolving
the high note side attenuated sound waveform data 218a output from the high note side
adder 207a in the filter calculation processor 203 with the left channel high note
side impulse response waveform data (second sound waveform data) 121a read from the
memory 104. Similarly, when the performer depresses the damper pedal 150 illustrated
in FIG. 1, the low note side convolution operation processor 204b performs a process
of convolving the low note side attenuated sound waveform data 218b output from the
low note side adder 207b in the filter calculation processor 203 with the left channel
low note side impulse response waveform data (second sound waveform data) 121b read
from the memory 104. An adder 220 then generates the third sound waveform data (L-ch)
113 by adding together (mixing together) the output waveform data from the high note
side convolution operation processor 204a and the low note side convolution operation
processor 204b.
[0052] In order to implement the process described above, the high note side convolution
operation processor 204a includes a Fast Fourier transform (FFT) convolver 213a, a
multiplier 214a arranged on the input side of the FFT convolver 213a, a multiplier
215a arranged on the output side of the FFT convolver 213a, and envelope generators
(EGs) 216a and 217a that respectively generate scaling factor change information for
the multipliers 214a and 215a. Similarly, the low note side convolution operation
processor 204b includes an FFT convolver 213b, a multiplier 214b arranged on the input
side of the FFT convolver 213b, a multiplier 215b arranged on the output side of the
FFT convolver 213b, and EGs 216b and 217b that respectively generate scaling factor
change information for the multipliers 214b and 215b. The FFT convolvers 213a and
213b, the multipliers 214a and 214b, the multipliers 215a and 215b, the EGs 216a and
216b, and the EGs 217a and 217b respectively have the same configurations except in
that the data processed is for the left channel and for the right channel.
[0053] The FFT convolver 213a stores, in an internal register, impulse response data corresponding
to impulse responses obtained by sampling string vibration and body characteristics
on the high note side of an acoustic piano while depressing the damper pedal. Similarly,
the FFT convolver 213b stores, in an internal register, impulse response data corresponding
to impulse responses obtained by sampling string vibration and body characteristics
on the low note side of the acoustic piano while depressing the damper pedal. Furthermore,
the FFT convolver 213a performs an operation process of convolving the high note side
attenuated sound waveform data 218a output from the high note side adder 207a in the
filter calculation processor 203 with the high note side impulse response data, and
then outputs the resulting high note side resonant tone waveform data. Similarly,
the FFT convolver 213b performs an operation process of convolving the low note side
attenuated sound waveform data 218b output from the low note side adder 207b in the
filter calculation processor 203 with the low note side impulse response data, and
then outputs the resulting low note side resonant tone waveform data.
[0054] Here, in order to produce the behavior for when the performer depresses the damper
pedal 150 illustrated in FIG. 1, the high note side convolution operation processor
204a utilizes the multipliers 214a and 215a arranged before and after the FFT convolver
213a as well as the EGs 216a and 217a that control the multiplication factors of the
multipliers 214a and 215a to manipulate the volume before and after the FFT convolver
213a. Similarly, in order to produce the behavior for when the performer depresses
the damper pedal 150, the low note side convolution operation processor 204b utilizes
the multipliers 214b and 215b arranged before and after the FFT convolver 213b as
well as the EGs 216b and 217b that control the multiplication factors of the multipliers
214b and 215b to manipulate the volume before and after the FFT convolver 213b. When
the performer depresses the damper pedal 150, the CPU 103 inputs damper pedal depression
information 118 indicating that the damper pedal is ON to the EGs 216a, 217a, 216b,
and 217b via the system bus 170. Conversely, when the performer releases the damper
pedal 150, the CPU 103 inputs damper pedal depression information 118 indicating that
the damper pedal is OFF to the EGs 216a, 217a, 216b, and 217b via the system bus 170.
The EGs 216a, 217a, 216b, and 217b generate envelope values for when the damper pedal
is ON and envelope values for when the damper pedal is OFF in accordance with the
damper pedal depression information 118 and then respectively apply these values to
the multipliers 214a, 215a, 214b, and 215b. In this way, the amount of damper pedal
effect for when the damper pedal is ON or OFF is controlled with the multipliers 214a,
215a, 214b, and 215b. In an acoustic piano, the impulse length of the resonance from
string vibration is relatively long (several dozen seconds, for example), and therefore
here, if only the multipliers 215a and 215b on the output sides of the FFT convolver
213a and the FFT convolver 213b are present, any residual sound in the FFT convolver
213a or the FFT convolver 213b could potentially be output again. To prevent this,
the multipliers 214a and 214b are also arranged on the input sides of the FFT convolver
213a and the FFT convolver 213b to control the amount of damper pedal effect.
[0055] FIG. 5 is a block diagram illustrating an example of an embodiment of the FFT convolver
213a or 213b illustrated in FIG. 2. The FFT convolver 213a or 213b includes an FFT
processor 501, an impulse response waveform data register 502, a delay unit 503, a
complex multiplier 504, a complex adder 505, and an inverse FFT processor 506.
[0056] The FFT processor 501 performs an FFT calculation on the high note side attenuated
sound waveform data 218a or the low note side attenuated sound waveform data 218b
that is input.
[0057] The impulse response waveform data register 502 stores impulse response complex number
frequency waveform data 121a or 121b sent from the memory 104 via the system bus 170
by the CPU 103 illustrated in FIG. 1.
[0058] The delay unit 503 stores complex number frequency waveform data from the FFT processor
501 while shifting that data by an analysis frame unit or half of that unit.
[0059] The complex multiplier 504, in accordance with equation 6 below, and for each frequency,
performs complex multiplication of the impulse response frequency waveform data stored
in the impulse response waveform data register 502 with the frequency waveform data
stored in the delay unit 503.
![](https://data.epo.org/publication-server/image?imagePath=2019/49/DOC/EPNWB1/EP17209236NWB1/imgb0006)
[0060] The complex adder 505 calculates the complex sum of the multiplication results from
the complex multiplier 504.
[0061] Then, the inverse FFT processor 506 performs an inverse FFT calculation on the output
of the complex adder 505 to generate resonant tone waveform data 507 and then outputs
this data to the multiplier 215a or 215b illustrated in FIG. 2.
[0062] FIG. 6 is an explanatory drawing of a method of recording the impulse response waveform
data (second sound waveform data). A high note side actuator and a low note side actuator
that cause the body of an acoustic piano to vibrate are arranged on the high note
side and the low note side of a frame that supports the strings of the acoustic piano,
and these actuators are driven separately to generate separate time-stretched pulse
(TSP) signals for the high note side and the low note side (S601a and S601b in FIG.
6).
[0063] The sound produced from the body of the acoustic piano due to TSP signals separately
generated for the high note side and for the low note side while depressing the damper
pedal is separately recorded for the high note side and the low note side using two
stereo microphones (S602 in FIG. 6). Although it would also be conceivable to make
the actuators generate impulse signals and then directly record the resulting pulse
responses, this would require the microphone gain and maximum actuator drive capability
to be excessively large as well as present challenges related to signal-to-noise ratio
(S/N), and therefore TSP signals are used. TSPs are a type of sweep waveform signal
generated by shifting the phase of an impulse for each frequency. TSPs make it possible
to disperse drive times for a certain period of time and are therefore effective for
solving the problems described above. Moreover, impulse hammers may be used instead
of the actuators to drive the piano. Furthermore, the number and positions of the
microphones that record the produced sound may be different from those illustrated
in FIG. 6, and TSP signals recorded at a plurality of locations above or below the
soundboard and then mixed together may be used.
[0064] The shifted phases of the recorded TSP signals are inverse-shifted to obtain time-domain
impulse response signals of the type shown in A in FIG. 6 (S603 in FIG. 6). These
impulse response signals are obtained separately for the high note side and for the
low note side.
[0065] FFT calculations are respectively performed separately for the high note side and
for the low note side on the obtained time-domain impulse response signals (S604 in
FIG. 6), thereby yielding the high note side impulse response waveform data (second
sound waveform data) 121a and the low note side impulse response waveform data (second
sound waveform data) 121b, which are complex number signals in the frequency domain,
and which are then stored in the memory 104 illustrated in FIG. 1 (S605 in FIG. 6).
[0066] FIGs. 7A to 7D are flowcharts illustrating examples of processes in the electronic
musical instrument 100 illustrated in FIG. 1 that are related to generating damper
sound effects. These processes are operations resulting from the execution of the
control programs stored in the memory 104 by the CPU 103 illustrated in FIG. 1.
[0067] FIG. 7A is a flowchart illustrating an example of a damper pedal ON interrupt process
executed when the performer depresses the damper pedal 150 illustrated in FIG. 1.
When this interrupt occurs, the CPU 103, via the system bus 170, inputs damper pedal
depression information 118 indicating that the damper pedal is ON to the EGs 216 and
217 (see FIG. 2) in the convolution operation processors 204 in the damper sound effect
generator (L-ch) 201 and the damper sound effect generator (R-ch) 202 included in
the damper sound effect generator 101 (see FIG. 1) (step S700 in FIG. 7A). The CPU
103 then returns from the interrupt. Due to this process, the EGs 216 and 217, in
accordance with the damper pedal depression information 118 indicating the damper
pedal ON instruction, respectively generate and apply the envelope values to the multipliers
214 and 215.
[0068] FIG. 7B is a flowchart illustrating an example of a damper pedal OFF interrupt process
executed when the performer releases the damper pedal 150 illustrated in FIG. 1 from
the depressed state. When this interrupt occurs, the CPU 103, via the system bus 170,
inputs damper pedal depression information 118 indicating that the damper pedal is
OFF to the EGs 216 and 217 (see FIG. 2) in the convolution operation processors 204
in the damper sound effect generator (L-ch) 201 and the damper sound effect generator
(R-ch) 202 included in the damper sound effect generator 101 (see FIG. 1) (step S710
in FIG. 7B). The CPU 103 then returns from the interrupt. Due to this process, the
EGs 216 and 217, in accordance with the damper pedal depression information 118 indicating
the damper pedal OFF instruction, respectively generate and apply the envelope values
to the multipliers 214 and 215.
[0069] FIG. 7C is a flowchart illustrating an example of an interrupt process for when the
performer operates the switch unit 160 to power on, change the temperament of, or
change the master tuning of the electronic musical instrument 100 illustrated in FIG.
1. When any of these interrupts occur, the CPU 103 recalculates the pitches corresponding
to the key numbers #0 to #87 in accordance with the respective key numbers and the
changed temperament or master tuning, and then, in accordance with the recalculated
pitches, recalculates the delay length K for the delayer (Delay) 208 in each of the
comb filters 206 corresponding to the key numbers #0 to #87 illustrated in FIG. 2
(step S720 in FIG. 7C). Moreover, the changed temperament information and master tuning
information are stored in a non-volatile memory (not illustrated in the figures),
and then when the interrupt triggered by powering on the electronic musical instrument
100 occurs, the temperament information and the master tuning information stored in
the non-volatile memory are used for the recalculations described above.
[0070] The CPU 103 then, via the system bus 170, sets, as the pitch control signal 119,
the recalculated delay length K for each comb filter 206 to the register Reg#1 211
in each of the comb filters 206 in the damper sound effect generator (L-ch) 201 and
the damper sound effect generator (R-ch) 202 included in the damper sound effect generator
101 (see FIG. 1) (step S721 in FIG. 7C).
[0071] Moreover, when the interrupt triggered by powering on the electronic musical instrument
100 occurs, the CPU 103 reads the scaling factors α for the multipliers 209 in the
comb filters 206 corresponding to the key numbers #0 to #87 illustrated in FIG. 2
from a read-only memory (ROM), for example (not illustrated in the figures), and then,
via the system bus 170, sets these scaling factors, as the resonant effect reduction
amount configuration signal 120, to the registers Reg#2 212 (see FIG. 2) in the comb
filters 206 in the damper sound effect generator (L-ch) 201 and the damper sound effect
generator (R-ch) 202 included in the damper sound effect generator 101 (see FIG. 1)
(step S722 in FIG. 7C). The CPU 103 then returns from the interrupt.
[0072] FIG. 7D is a flowchart illustrating an example of an interrupt process for when the
performer operates the switch unit 160 to change the amount of damper pedal effect
to apply. When this interrupt occurs, the CPU 103 sets the damper pedal effect application
amount configuration signal 122 configured with the changed application amount to
the multipliers 105 and 106 (see FIG. 1) via the system bus 170. The CPU 103 then
returns from the interrupt. Thus, the application amount is changed in the third sound
waveform data (L-ch) 113 and the third sound waveform data (R-ch) 114 (that is, the
resonant tones for the damper pedal effect from the damper sound effect generator
101) that are respectively added into the piano sound waveform data (L-ch) 115 and
the piano sound waveform data (R-ch) 116 by the adders 107 and 108 illustrated in
FIG. 1.
[0073] The embodiment described above utilizes a method based on convolving resonant tone
characteristics sampled directly from an acoustic piano to generate and add together
the correct damper sound effects, thereby making it possible to obtain piano damper
sounds and piano sounds that are more natural, realistic, and beautiful.
[0074] Although in the embodiment described above the convolution operation processes were
performed divided into two types, the high note side and the low note side, the convolution
operation processes may be performed divided into more types. In such a case, for
the impulse response waveform data (second sound waveform data) 121 that is stored
in the memory 104 in advance, a plurality of types of data corresponding to the divided
types may be stored and selected from.
[0075] Although the embodiment described above outputs two-channel stereo musical notes,
the output does not necessarily need to be stereo output, or the output may be three
or more channel stereo output.
[0076] In the embodiment described above, the number of comb filters 206 prepared matches
the 88 keys #0 to #87 corresponding to the number of strings in a standard acoustic
piano. However, when the amount of delay is long, such as for bass strings, a configuration
in which the delay lengths K for the delayers (Delay) 208 are set to half the periods
of the pitches corresponding to the key numbers or a configuration in which some of
the comb filters are shared for other strings may be used.
[0077] Although the embodiment described above uses FFT calculations as an example of the
convolution operation processes performed by the convolution operation processors
204, the convolution operation processes may alternatively be performed by direct
multiplication-accumulation of the waveform data in the time domain without using
FFTs.
[0078] It will be apparent to those skilled in the art that various modifications and variations
can be made in the present invention without departing from the scope of the invention.
Thus, it is intended that the present invention cover modifications and variations
that come within the scope of the appended claims.
1. A musical note generation device, comprising:
a plurality of keys, the plurality of keys respectively being associated with pitch
information; and
at least one processor, the at least one processor performing the following processes:
an attenuated sound waveform data generation process of generating attenuated sound
waveform data by respectively reducing, among frequency components included in first
sound waveform data corresponding to the pitch information associated with a specified
key, amplitudes of respective frequency components of a fundamental tone and harmonics
of the fundamental tone corresponding to a pitch indicated by the pitch information;
a convolution operation process that convolves the attenuated sound waveform data
generated by the attenuated sound waveform data generation process with at least one
of a plurality of second sound waveform data sets respectively corresponding to at
least one of a higher pitch side impulse response and a lower pitch side impulse response,
so as to generate third sound waveform data, the higher pitch side impulse response
having relatively higher pitch components than the lower pitch side impulse response;
and
an output process of outputting piano sound waveform data generated on the basis of
the third sound waveform data generated by the convolution operation process,
wherein in the attenuated sound waveform data generation process, the at least one
processor identifies the respective frequency components of the fundamental tone and
the harmonics with a comb filter.
2. The musical note generation device according to claim 1,
wherein the first sound waveform data includes at least a sound obtained from vibration
of a string struck due to a keypress being performed while not depressing a damper
pedal in a keyboard instrument, and
wherein the plurality of sets of second sound waveform data are impulse response waveform
data for resonant tones obtained from vibration of a plurality of strings included
in the keyboard instrument that is caused by vibrating at least one of a higher pitch
side and a lower pitch side of the keyboard instrument while depressing the damper
pedal of the keyboard instrument.
3. The musical note generation device according to claim 1, wherein in the convolution
operation process, when a key on a lower pitch side is pressed, the attenuated sound
waveform data is convolved with the second sound waveform data corresponding to the
lower pitch side impulse response, and when a key on a higher pitch side is pressed,
the attenuated sound waveform data is convolved with the second sound waveform data
corresponding to the higher pitch side impulse response.
4. The musical note generation device according to claim 1, wherein in the attenuated
sound waveform data generation process, the at least one processor generates the attenuated
sound waveform data by performing a delay process corresponding to the specified key
on the first sound waveform data.
5. The musical note generation device according to claim 1, wherein the at least one
processor performs the attenuated sound waveform data generation process, the convolution
operation process, and the output process when a damper pedal is depressed.
6. The musical note generation device according to claim 1, wherein
the convolution operation process convolves the attenuated sound waveform data with
a plurality of second sound waveform data sets.
7. The musical note generation device according to claim 6, wherein the at least one
processor performs the following processes:
in the attenuated sound waveform data generation process, a process of generating
first attenuated sound waveform data by multiplying, by a high sound range side effect
application factor, sound waveform data in which the amplitudes of the respective
frequency components of the fundamental tone and harmonics are respectively reduced,
and a process of generating second attenuated sound waveform data by multiplying,
by a low sound range side effect application factor, the sound waveform data in which
the amplitudes of the respective frequency components of the fundamental tone and
harmonics are respectively reduced, and
in the convolution operation process, a process of convolving the first attenuated
sound waveform data with the second sound waveform data set corresponding to the higher
pitch side impulse response, a process of convolving the second attenuated sound waveform
data with the second sound waveform data set corresponding to the lower pitch side
impulse response, and a process of generating the third sound waveform data from the
respectively convolved sound waveform data.
8. An electronic musical instrument, comprising:
a damper pedal; and
the musical note generation device as set forth in claim 1,
wherein the at least one processor of the musical note generating device performs
the attenuated sound waveform data generation process, the convolution operation process,
and the output process when the damper pedal is depressed.
9. A method to be executed by a processor in an electronic musical instrument, comprising:
an attenuated sound waveform data generation process of generating attenuated sound
waveform data by respectively reducing, among frequency components included in first
sound waveform data corresponding to pitch information associated with a specified
key, amplitudes of respective frequency components of a fundamental tone and harmonics
of the fundamental tone corresponding to a pitch indicated by the pitch information;
a convolution operation process that convolves the attenuated sound waveform data
generated by the attenuated sound waveform data generation process with at least one
of a plurality of second sound waveform data sets respectively corresponding to at
least one of a higher pitch side impulse response and a lower pitch side impulse response,
so as to generate third sound waveform data, the higher pitch side impulse response
having relatively higher pitch components than the lower pitch side impulse response;
and
an output process of outputting piano sound waveform data generated on the basis of
the third sound waveform data generated by the convolution operation process,
wherein in the attenuated sound waveform data generation process, the at least one
processor identifies the respective frequency components of the fundamental tone and
the harmonics with a comb filter.
10. A non-transitory storage medium having stored therein instructions that cause a processor
in an electronic musical instrument to perform the following processes:
an attenuated sound waveform data generation process of generating attenuated sound
waveform data by respectively reducing, among frequency components included in first
sound waveform data corresponding to pitch information associated with a specified
key, amplitudes of respective frequency components of a fundamental tone and harmonics
of the fundamental tone corresponding to a pitch indicated by the pitch information;
a convolution operation process that convolves the attenuated sound waveform data
generated by the attenuated sound waveform data generation process with at least any
one of a plurality of second sound waveform data sets respectively corresponding to
at least one of a higher pitch side impulse response and a lower pitch side impulse
response, so as to generate third sound waveform data, the higher pitch side impulse
response having relatively higher pitch components than the lower pitch side impulse
response; and
an output process of outputting piano sound waveform data generated on the basis of
the third sound waveform data generated by the convolution operation process,
wherein in the attenuated sound waveform data generation process, the at least one
processor identifies the respective frequency components of the fundamental tone and
the harmonics with a comb filter.
1. Musiknotenerzeugungsvorrichtung, umfassend:
eine Vielzahl von Tasten, wobei die Vielzahl von Tasten jeweils mit Tonhöheninformationen
verbunden ist; und
zumindest einen Prozessor, wobei der zumindest eine Prozessor die folgenden Vorgänge
durchführt:
einen gedämpften Tonwellenformdatenerzeugungsvorgang des Erzeugens von gedämpften
Tonwellenformdaten durch jeweiliges Reduzieren, unter Frequenzkomponenten, die in
ersten Tonwellenformdaten entsprechend den Tonhöheninformationen in Verbindung mit
einer bestimmten Taste enthalten sind, von Amplituden jeweiliger Frequenzkomponenten
eines Fundamentaltons und von Oberwellen des Fundamentaltons entsprechend einer Tonhöhe,
die durch die Tonhöheninformationen angegeben ist;
einen Faltungsoperationsvorgang, der die gedämpften Tonwellenformdaten, die durch
den gedämpften Tonwellenformdatenerzeugungsvorgang erzeugt werden, mit zumindest einem
aus einer Vielzahl von zweiten Tonwellenformdatensätzen, die jeweils zumindest einem
von einer höheren Tonhöhenseitenimpulsantwort und einer niedrigeren Tonhöhenseitenimpulsantwort
entsprechen, faltet, um so dritte Tonwellenformdaten zu erzeugen, wobei die höhere
Tonhöhenseitenimpulsantwort relativ höhere Tonhöhenkomponenten aufweist als die niedrigere
Tonhöhenseitenimpulsantwort; und
einen Ausgabevorgang des Ausgebens von Klaviertonwellenformdaten, die auf Grundlage
der dritten Tonwellenformdaten erzeugt werden, die durch den Faltungsoperationsvorgang
erzeugt werden,
wobei in dem gedämpften Tonwellenformdatenerzeugungsvorgang der zumindest eine Prozessor
die jeweiligen Frequenzkomponenten des Fundamentaltons und der Oberwellen mit einem
Kammfilter identifiziert.
2. Musiknotenerzeugungsvorrichtung nach Anspruch 1,
wobei die ersten Tonwellenformdaten zumindest einen Ton beinhalten, der durch Vibration
einer Saite erhalten wird, die aufgrund eines Tastendrucks angeschlagen wird, der
durchgeführt wird, während kein Dämpferpedal in einem Keyboardinstrument hinuntergedrückt
wird, und
wobei die Vielzahl von Sätzen von zweiten Tonwellenformdaten Impulsantwortwellenformdaten
für Resonanztöne sind, die durch Vibration einer Vielzahl von Saiten erhalten werden,
die in dem Keyboardinstrument enthalten ist, die bewirkt wird, indem zumindest eine
von einer höheren Tonhöhenseite und einer niedrigeren Tonhöhenseite des Keyboardinstrument
in Vibration versetzt wird, während das Dämpferpedal des Keyboardinstruments hinuntergedrückt
wird.
3. Musiknotenerzeugungsvorrichtung nach Anspruch 1, wobei bei dem Faltungsoperationsvorgang,
wenn eine Taste an einer niedrigeren Tonhöhenseite gedrückt wird, die gedämpften Tonwellenformdaten
mit den zweiten Tonwellenformdaten entsprechend der niedrigeren Tonhöhenseitenimpulsantwort
gefaltet werden, und wenn eine Taste an einer höheren Tonhöhenseite gedrückt wird,
die gedämpften Tonwellenformdaten mit den zweiten Tonwellenformdaten entsprechend
der höheren Tonhöhenseitenimpulsantwort gefaltet werden.
4. Musiknotenerzeugungsvorrichtung nach Anspruch 1, wobei bei dem gedämpften Tonwellenformdatenerzeugungsvorgang
der zumindest eine Prozessor die gedämpften Tonwellenformdaten erzeugt, indem ein
Verzögerungsvorgang entsprechend der bestimmten Taste an den ersten Tonwellenformdaten
durchgeführt wird.
5. Musiknotenerzeugungsvorrichtung nach Anspruch 1, wobei der zumindest eine Prozessor
den gedämpften Tonwellenformdatenerzeugungsvorgang, den Faltungsoperationsvorgang
und den Ausgabevorgang durchführt, wenn ein Dämpferpedal hinuntergedrückt wird.
6. Musiknotenerzeugungsvorrichtung nach Anspruch 1, wobei der Faltungsoperationsvorgang
die gedämpften Tonwellenformdaten mit einer Vielzahl von zweiten Tonwellenformdatensätzen
faltet.
7. Musiknotenerzeugungsvorrichtung nach Anspruch 6, wobei der zumindest eine Prozessor
die folgenden Vorgänge durchführt:
bei dem gedämpften Tonwellenformdatenerzeugungsvorgang, einen Vorgang des Erzeugens
von ersten gedämpften Tonwellenformdaten durch Multiplizieren, mit einem hohen Tonbereichsseiteneffektanwendungsfaktor,
von Tonwellenformdaten, bei denen die Amplituden der jeweiligen Frequenzkomponenten
des Fundamentaltons und der Oberwellen jeweils reduziert sind, und einen Vorgang des
Erzeugens von zweiten gedämpften Tonwellenformdaten durch Multiplizieren, mit einem
niedrigen Tonbereichsseiteneffektanwendungsfaktor, der Tonwellenformdaten, bei denen
die Amplituden der jeweiligen Frequenzkomponenten des Fundamentaltons und der Oberwellen
jeweils reduziert sind, und
bei dem Faltungsoperationsvorgang, einen Vorgang des Faltens der ersten gedämpften
Tonwellenformdaten mit dem zweiten Tonwellenformdatensatz entsprechend der höheren
Tonhöhenseitenimpulsantwort, einen Vorgang des Faltens der zweiten gedämpften Tonwellenformdaten
mit dem zweiten Tonwellenformdatensatz entsprechend der niedrigeren Tonhöhenseitenimpulsantwort
und einen Vorgang des Erzeugens der dritten Tonwellenformdaten aus den jeweils gefalteten
Tonwellenformdaten.
8. Elektronisches Musikinstrument, umfassend:
ein Dämpferpedal; und
die Musiknotenerzeugungsvorrichtung nach Anspruch 1,
wobei der zumindest eine Prozessor der Musiknotenerzeugungsvorrichtung den gedämpften
Tonwellenformdatenerzeugungsvorgang, den Faltungsoperationsvorgang und den Ausgabevorgang
durchführt, wenn das Dämpferpedal hinuntergedrückt wird.
9. Verfahren, das durch einen Prozessor in einem elektronischen Musikinstrument auszuführen
ist, umfassend:
einen gedämpften Tonwellenformdatenerzeugungsvorgang des Erzeugens von gedämpften
Tonwellenformdaten durch jeweiliges Reduzieren, unter Frequenzkomponenten, die in
ersten Tonwellenformdaten entsprechend den Tonhöheninformationen in Verbindung mit
einer bestimmten Taste enthalten sind, von Amplituden jeweiliger Frequenzkomponenten
eines Fundamentaltons und von Oberwellen des Fundamentaltons entsprechend einer Tonhöhe,
die durch die Tonhöheninformationen angegeben ist;
einen Faltungsoperationsvorgang, der die gedämpften Tonwellenformdaten, die durch
den gedämpften Tonwellenformdatenerzeugungsvorgang erzeugt werden, mit zumindest einem
aus einer Vielzahl von zweiten Tonwellenformdatensätzen, die jeweils zumindest einem
von einer höheren Tonhöhenseitenimpulsantwort und einer niedrigeren Tonhöhenseitenimpulsantwort
entsprechen, faltet, um so dritte Tonwellenformdaten zu erzeugen, wobei die höhere
Tonhöhenseitenimpulsantwort relativ höhere Tonhöhenkomponenten aufweist als die niedrigere
Tonhöhenseitenimpulsantwort; und
einen Ausgabevorgang des Ausgebens von Klaviertonwellenformdaten, die auf Grundlage
der dritten Tonwellenformdaten erzeugt werden, die durch den Faltungsoperationsvorgang
erzeugt werden,
wobei in dem gedämpften Tonwellenformdatenerzeugungsvorgang der zumindest eine Prozessor
die jeweiligen Frequenzkomponenten des Fundamentaltons und der Oberwellen mit einem
Kammfilter identifiziert.
10. Nichtflüchtiges Speichermedium, auf dem Anweisungen gespeichert sind, die einen Prozessor
in einem elektronischen Musikinstrument dazu veranlassen, die folgenden Vorgänge durchzuführen:
einen gedämpften Tonwellenformdatenerzeugungsvorgang des Erzeugens von gedämpften
Tonwellenformdaten durch jeweiliges Reduzieren, unter Frequenzkomponenten, die in
ersten Tonwellenformdaten entsprechend den Tonhöheninformationen in Verbindung mit
einer bestimmten Taste enthalten sind, von Amplituden jeweiliger Frequenzkomponenten
eines Fundamentaltons und von Oberwellen des Fundamentaltons entsprechend einer Tonhöhe,
die durch die Tonhöheninformationen angegeben ist;
einen Faltungsoperationsvorgang, der die gedämpften Tonwellenformdaten, die durch
den gedämpften Tonwellenformdatenerzeugungsvorgang erzeugt werden, mit zumindest einem
beliebigen aus einer Vielzahl von zweiten Tonwellenformdatensätzen, die jeweils zumindest
einem von einer höheren Tonhöhenseitenimpulsantwort und einer niedrigeren Tonhöhenseitenimpulsantwort
entsprechen, faltet, um so dritte Tonwellenformdaten zu erzeugen, wobei die höhere
Tonhöhenseitenimpulsantwort relativ höhere Tonhöhenkomponenten aufweist als die niedrigere
Tonhöhenseitenimpulsantwort; und
einen Ausgabevorgang des Ausgebens von Klaviertonwellenformdaten, die auf Grundlage
der dritten Tonwellenformdaten erzeugt werden, die durch den Faltungsoperationsvorgang
erzeugt werden,
wobei in dem gedämpften Tonwellenformdatenerzeugungsvorgang der zumindest eine Prozessor
die jeweiligen Frequenzkomponenten des Fundamentaltons und der Oberwellen mit einem
Kammfilter identifiziert.
1. Dispositif générateur de notes de musique, comprenant :
une pluralité de touches, la pluralité de touches étant associée respectivement à
des informations sur le timbre ; et
au moins un processeur, l'au moins un processeur exécutant des processus, y compris
:
un processus de génération de données de courbes sonores atténuées générant des données
de courbes sonores atténuées, par la réduction respective, parmi des composantes fréquentielles
comprises dans les premières données de courbes sonores correspondant aux informations
sur le timbre associées à une touche spécifiée, des amplitudes de composantes fréquentielles
respectives d'une tonalité fondamentale et d'harmoniques de la tonalité fondamentale
correspondant à un timbre indiqué par les informations sur le timbre ;
un processus d'opération de convolution convolutionnant des données de courbes sonores
atténuées générées par le processus de génération de données de courbes sonores atténuées,
au moins un d'une pluralité d'ensembles de deuxièmes jeux de données de courbes sonores
correspondant respectivement à au moins une d'une réponse impulsionnelle du côté au
timbre plus aigu et une réponse impulsionnelle d'un côté au timbre plus grave, de
façon à générer des données de troisièmes courbes sonores, la réponse impulsionnelle
du côté du timbre plus aigu possédant des composants au timbre relativement plus aigu
que la réponse impulsionnelle du côté du timbre plus grave ; et
un processus d'émission pour l'émission de données de courbes sonores de piano générées
en fonction des données de troisièmes courbes sonores générées par le processus d'opération
de convolution,
l'au moins un processeur identifiant, dans le processus de génération de données de
courbes sonores atténuées, les composantes fréquentielles respectives de la tonalité
fondamentale et les harmoniques avec un filtre-peigne.
2. Dispositif générateur de notes de musique selon la revendication 1,
les premières données de courbes sonores comprenant au moins un son obtenu par la
vibration d'une corde frappée à la suite d'une pression de touche effectuée tout en
n'appuyant pas sur une pédale de sourdine dans un instrument à clavier, et
la pluralité d'ensembles de deuxièmes données de courbes sonores étant des données
de courbes sonores de réponse impulsionnelle pour des tonalités résonantes obtenues
de vibrations d'une pluralité de cordes comprises dans l'instrument à clavier, causées
par la vibration d'au moins un d'un côté du timbre plus aigu et un côté du timbre
plus grave de l'instrument à clavier tout en appuyant sur la pédale de sourdine de
l'instrument à clavier.
3. Dispositif générateur de notes de musique selon la revendication 1, dans lequel, lorsqu'au
cours du processus d'opération de convolution, on appuie sur une touche du côté du
timbre plus grave, les données de courbes sonores atténuées sont convolutionnées avec
les deuxièmes données de courbes sonores correspondant à la réponse impulsionnelle
du côté du timbre plus grave, et lorsque l'on appuie sur une touche du côté du timbre
plus aigu, les données de courbes sonores atténuées sont convolutionnées avec les
deuxièmes données de courbes sonores correspondant à la réponse impulsionnelle du
côté du timbre plus aigu.
4. Dispositif générateur de notes de musique selon la revendication 1, dans lequel, dans
le processus de génération de données de courbes sonores atténuées, l'au moins un
processeur génère les données de courbes sonores atténuées en effectuant un processus
de temporisation correspondant à la touche spécifiée sur les premières données de
courbes sonores.
5. Dispositif générateur de notes de musique selon la revendication 1, l'au moins un
processeur effectuant le processus de génération de données de courbes sonores atténuées,
le processus d'opération de convolution, et le processus d'émission lorsque l'on appuie
sur une pédale de sourdine.
6. Dispositif générateur de notes de musique selon la revendication 1, dans lequel :
le processus d'opération de convolution assure la convolution des données de courbes
sonores atténuées avec une pluralité d'ensembles de deuxièmes données de courbes sonores.
7. Dispositif générateur de notes de musique selon la revendication 6, l'au moins un
processeur effectuant les processus suivants :
dans le processus de génération de données de courbes sonores atténuées, un processus
de génération de premières données de courbes sonores atténuées en multipliant, par
un facteur d'application d'un effet d'un côté de la plage des sons aigus, des données
de courbes sonores dans lesquelles les amplitudes des composantes fréquentielles respectives
de la tonalité fondamentale et des harmoniques sont réduites respectivement, et un
processus de génération de deuxièmes données de courbes sonores atténuées en multipliant,
par un facteur d'application d'un effet d'un côté de la plage des sons graves, les
données de courbes sonores dans lesquelles les amplitudes des composantes fréquentielles
respectives de la tonalité fondamentale et des harmoniques sont réduites respectivement,
et
dans le processus d'opération de convolution, un processus de convolution des premières
données de courbes sonores atténuées avec les deuxièmes données de courbes sonores
atténuées correspondant à la réponse impulsionnelle côté timbre plus aigu, un processus
de convolution des deuxièmes données de courbes sonores atténuées avec l'ensemble
des deuxièmes données de courbes sonores atténuées correspondant à la réponse impulsionnelle
côté timbre plus grave, et un processus de génération des troisièmes données de courbes
sonores d'après les données de courbes sonores convolutionnées respectivement.
8. Instrument musical électronique comprenant :
une pédale de sourdine ; et
le dispositif générateur de notes de musique selon la revendication 1,
l'au moins un processeur du dispositif générateur de notes de musique effectuant le
processus de génération de données de courbes sonores atténuées, le processus d'opération
de convolution, et le processus d'émission lorsque l'on appuie sur la pédale de sourdine.
9. Méthode effectuée par au moins un processeur dans un instrument musical, comprenant
:
un processus de génération de données de formes d'ondes sonores atténuées pour la
génération de données de formes d'ondes sonores atténuées en réduisant respectivement,
parmi les composantes fréquentielles comprises dans les premières données de formes
d'ondes sonores correspondant aux informations sur le timbre associées à une touche
spécifiée, des amplitudes de composantes fréquentielles respectives d'une tonalité
fondamentale et d'harmoniques de la tonalité fondamentale correspondant à un timbre
indiqué par les informations sur le timbre ;
un processus d'opération de convolution convolutionnant les données de courbes sonores
atténuées générées par le processus de génération de données de courbes sonores atténuées,
au moins un d'une pluralité de deuxièmes ensembles de données de courbes sonores correspondant
respectivement à au moins une d'une réponse impulsionnelle du côté au timbre plus
aigu et d'une réponse impulsionnelle d'un côté au timbre plus grave, de façon à générer
des données de troisièmes courbes sonores, la réponse impulsionnelle du côté du timbre
plus aigu possédant des composantes au timbre relativement plus aigu que la réponse
impulsionnelle du côté du timbre plus grave ; et
un processus d'émission pour l'émission de données de courbes sonores de piano générées
en fonction des données de troisièmes courbes sonores générées par le processus d'opération
de convolution,
l'au moins un processeur identifiant, dans le processus de génération de données de
courbes sonores atténuées, les composantes fréquentielles respectives de la tonalité
fondamentale et des harmoniques avec un filtre-peigne.
10. Support de stockage non transitoire dans lequel sont stockées des instructions causant
l'exécution, par un processeur dans un instrument de musique électronique, des processus
suivants :
un processus de génération de données de courbes sonores atténuées pour la génération
de données de courbes sonores atténuées en réduisant respectivement, parmi les composantes
fréquentielles comprises dans les premières données de courbes sonores correspondant
aux informations sur le timbre associées à une touche spécifiée, des amplitudes de
composantes fréquentielles respectives d'une tonalité fondamentale et d'harmoniques
de la tonalité fondamentale correspondant à un timbre indiqué par les informations
sur le timbre ;
un processus d'opération de convolution convolutionnant les données de courbes sonores
atténuées générées par le processus de génération de données de courbes sonores atténuées,
au moins un d'une pluralité de deuxièmes ensembles de données de courbes sonores correspondant
respectivement à au moins une d'une réponse impulsionnelle du côté au timbre plus
aigu et d'une réponse impulsionnelle d'un côté au timbre plus grave, de façon à générer
des données de troisièmes courbes sonores, la réponse impulsionnelle du côté du timbre
plus aigu possédant des composantes au timbre relativement plus aigu que la réponse
impulsionnelle du côté du timbre plus grave ; et
un processus d'émission pour l'émission de données de courbes sonores de piano générées
en fonction des données de troisièmes courbes sonores générées par le processus d'opération
de convolution,
l'au moins un processeur identifiant, dans le processus de génération de données de
courbes sonores atténuées, les composantes fréquentielles respectives de la tonalité
fondamentale et des harmoniques avec un filtre-peigne.